Fixed compatibility with older scrapy releases

Author: ncadou

scrapy_webdriver/download.py

@@ -1,10 +1,14 @@
-from scrapy import log
+from scrapy import log, version_info
 from scrapy.utils.decorator import inthread
 from scrapy.utils.misc import load_object
 
 from .http import WebdriverActionRequest, WebdriverRequest, WebdriverResponse
 
-FALLBACK_HANDLER = 'scrapy.core.downloader.handlers.http10.HTTP10DownloadHandler'  # NOQA
+if map(int, version_info) < [0, 18]:
+    FALLBACK_HANDLER = 'http.HttpDownloadHandler'
+else:
+    FALLBACK_HANDLER = 'http10.HTTP10DownloadHandler'
+FALLBACK_HANDLER = 'scrapy.core.downloader.handlers.%s' % FALLBACK_HANDLER
 
 
 class WebdriverDownloadHandler(object):

scrapy_webdriver/selector.py

@@ -1,6 +1,9 @@
 import re
 
-from scrapy.selector import Selector, XPathSelectorList
+try:
+    from scrapy.selector import Selector, XPathSelectorList
+except ImportError:  # scrapy < 0.20
+    from scrapy.selector import XPathSelector as Selector, XPathSelectorList
 
 _UNSUPPORTED_XPATH_ENDING = re.compile(r'.*/((@)?([^/()]+)(\(\))?)$')